Most legal disputes involving state law initially are decided by trial courts or certain administrative agencies. After such a decision, a party may seek appellate review of the ruling if that party believes the trial court or administrative agency made an error of law that harmed the party.

In cases other than death penalty appeals, a party seeks appellate review in the Court of Appeal. After the Court of Appeal has made its decision, a party may seek review in the California Supreme Court. Death penalty appeals are decided only by the Supreme Court, not by the courts of appeal.

Thousands of cases are appealed in California every year. They include criminal convictions; civil cases involving personal injury, contract, employment, real estate, probate, dissolution of marriage, child custody and many other issues; and administrative matters, such as worker's compensation. In the vast majority of these cases, the decision of the Court of Appeal is the final decision. This is because the Supreme Court grants review of only a few Court of Appeal decisions when necessary to resolve novel or disputed questions of law. Proceedings in appellate courts are very different from those in trial courts. In trial courts, a judge or jury hears the testimony of witnesses and reviews physical evidence, exhibits and documents, then decides which version to believe and reaches a decision.

Appellate courts, on the other hand, do not decide an appeal by taking new evidence or reassessing the credibility of the witnesses who testified in the trial court. Rather, they review the written record to determine if the trial court properly interpreted the law and used the correct procedures when considering the case.

To ensure cases are examined from several perspectives, each appeal is considered by a panel of three justices. Appellate court justices are assisted in their review by the parties' written and oral arguments. To decide a case a majority of the justices must agree. Whenever an appellate court reverses, it almost always allows the trial court to rehear the case using the correct law and procedures.

All justices are bound to apply the law whether or not they personally agree with it. Justices may not substitute their own ideas for what the law should be, but are bound by the federal and state constitutions, statutes, and other rules and regulations enacted by those with the authority to do so, including the State Legislature and the voters by initiative. Justices must enforce all laws without being swayed by public opinion. The Code of Judicial Ethics requires all justices to "be faithful to the law regardless of partisan interests, public clamor or fear of criticism . . . ." The retention election system, adopted by California voters as part of the state Constitution, is designed specifically to foster judicial independence from improper external pressures.

The California Constitution generally requires appellate courts to decide a case in a written opinion setting forth the facts and rules of law upon which the decision is made. By constitutional mandate, the decision must be issued within 90 days after the case has been taken under submission or the justices hearing the case cannot receive their pay.

While appellate court justices perform their roles quietly and without fanfare, the public can find much of their work published in law books titled "California Reports," "California Appellate Reports" and "California Reporter." Each of California's 58 counties has a public law library containing these books, as do law schools and most law offices.